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Genetics: DNA and inheritance

The Hardy-Weinberg equilibrium states that allele frequencies remain constant across generations unless certain influences are introduced, such as nonrandom matings or mutations.

Describe the Hardy-Weinberg principle.
Are there influences that deviate from the principle? If so, what are they? If no, why?
Deoxyribonucleic acid (DNA) profiling is a tool used in forensic investigation and paternity testing. This technique is often used by forensic scientists to identify individuals on the basis of their DNA profiles.

How is DNA profiling performed?
What are some of the novel uses of DNA profiling, other than those described in your textbook?
Sickle-cell disease is an example of balanced polymorphism as carriers of this disease are protected against malaria.

Describe an example of balanced polymorphism, other than sickle-cell disease, glucose-6-phosphate dehydrogenase (G6PD) deficiency, phenylketonuria (PKU), prior protein mutation, cystic fibrosis (CF), and Smith-Lemli-Opitz syndrome (SLOS).

Genetic ancestry testing is becoming popular as more and more people are trying to trace their ancestry. Two different types of tests are generally offered, mitochondrial DNA, which traces maternal lineages, and Y chromosome testing, which traces paternal lineages.

Does genetic ancestry testing provide a complete picture of a person's heritage? If so, how? If not, why not?

Solution Preview

The Hardy-Weinberg principle stated that evolution will not occur in a population if seven conditions are met: 1) mutation is not occurring; 2) natural selections is not occurring ; 3) the population is infinitely large ; 4) all members of the population breed; 5) all mating is totally random; 6) everyone produces the same number of offspring; 7) there in no migration in or out of the population. If there is evolution, these conditions are absence. In other words, if no mechanisms of evolution are acting on a population, evolution will not occur, and the gene pool frequencies will remain unchanged. The Hardy Weinbergy equilibrium equation ( P2 + 2pq + q2 = 1) is defined as the frequency of the dominant allele allele and q as the frequency of recessive allele for a trait controlled by a pair of alleles ( A and a). In other words, p equals all of the alleles in individuals who are homozygous dominant (AA) and half of the alleles in people who are heterozygous ( Aa) for this trait in a population. The Hardy Weinberg principle predict how gene frequencies will be inherited from generation to generation given a set of specific set of assumptions. The Hardy Weinberg principles states that in a large randomly breeding population, allelic frequencies will remain the same from generation to generation assuming that there is no mutation, gene migration, selection, or genetic drift.

Are there influences that deviate from the principle? If so, what are they? If no, why?

There are influences that deviate from the principle because in the real natural world, you know that there is always mutation that deviate from the Hardy Weinberg equilibrium. Mutation can occur spontaneously or induced by environmental factors, such as radiation, ultraviolet light, sunlight, or x-rays. These mutagens can cause mutations that will allow evolution to take place. There is evolution, there is no Hardy Weinberg. Genetic drift can also happen in real life and natural selection as well. For example, we tend to choose our mate and this nonrandom mating will deviate from Hardy Weinberg equilibrium.

Deoxyribonucleic acid (DNA) profiling is a tool used in forensic investigation and paternity testing. This technique is often used by forensic scientists to identify individuals on the basis of their DNA profiles.

How is DNA profiling performed?

DNA profiling is a technique ...

Solution Summary

The Hardy-Weinberg principle stated that evolution will not occur in a population if seven conditions are met: 1) mutation is not occurring; 2) natural selections is not occurring ; 3) the population is infinitely large ; 4) all members of the population breed; 5) all mating is totally random; 6) everyone produces the same number of offspring; 7) there in no migration in or out of the population. This solution discusses this further.

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